Sending, receiving, and organizing email in Outlook.com
Hello,
Outlook error 500 usually happens because of a corrupted cache and cookies stored in your web browser. This may conflict with the Outlook servers, and you may encounter this issue. To resolve this, first try signing in with your Microsoft Outlook account in an InPrivate window. See if you can sign in normally there.
If it works, clear your browsing history, cache, and cookies (All time), then log in to your account.
In some cases, switch between different web browsers might also help.
Alternatively, here's what you can try if you are still experiencing problems.
Open Command Prompt (Adminstrator) Window, run the command below and click Enter.
ipconfig /flushdns
netsh winsock reset
netsh int ip reset
This will reset internet connection on your device. Once done, restart your computer and see if you can access Outlook without any error.